savelog

savelog [-m mode] [-u user] [-g group] [-t] [-p] [-c cycle] [-l] [-j] [-J] [-1 .. -9] [-C] [-d] [-l] [-r rolldir] [-n] [-q] [-D dateformat] file ...

The savelog command saves and optionally compresses old copies of files. Older versions of file are named: file. where is the version number, 0 being the newest. Version num‐ bers > 0 are compressed unless -l prevents it. Version number 0 is not compressed because a process might still have file opened for I/O. Only cycle versions of the file are kept. If the file does not exist and -t was given, it will be created. For files that do exist and have lengths greater than zero, the follow‐ ing actions are performed: 1) Version numbered files are cycled. Version file.2 is moved to version file.3, version file.1 is moved to version file.2, and so on. Finally version file.0 is moved to version file.1, and version file is deleted. Both compressed names and uncompressed names are cycled, regardless of -l. Missing version files are ignored. 2) The new file.1 is compressed unless the -l flag was given. It is changed subject to the -m, -u, and -g flags. 3) The main file is moved to file.0. 4) If the -m, -u, -g, -t, or -p flags are given, then an empty file is created subject to the given flags. With the -p flag, the file is created with the same owner, group, and permissions as before. 5) The new file.0 is changed subject to the -m, -u, and -g flags.

-m mode chmod the log files to mode, implies -t -u user chown log files to user, implies -t -g group chgrp log files to group, implies -t -c cycle Save cycle versions of the logfile (default: 7). The cycle count must be at least 2. -t touch new logfile into existence -l don't compress any log files (default: do compress) -p preserve owner, group, and permissions of logfile -j compress with bzip2 instead of gzip -J compress with xz instead of gzip For xz no strength option is set, and xz decides on the default based on the total amount of physical RAM. Note that xz can use a very large amount of memory for the higher compression levels. -1 .. -9 compression strength or memory usage (default: 9, except for xz) -C force cleanup of cycled logfiles -d use standard date for rolling -D dateformat override date format, in the syntax understood by the date(1) command -r use rolldir instead of . to roll files -n do not rotate empty files -q be quiet

If a process is still writing to file.0, and savelog moves it to file.1 and compresses it, data could be lost.

logrotate(8)